<li class="treeview">
    <a href="#">
        <i class="fa fa-dashboard"></i> <span>Demo</span> 
    </a>
    <ul class="treeview-menu">
        <li><a href="{:addon_url('putong://demo/admin/index')}"><i class="fa "></i>demo插件</a></li>
    </ul>
</li>